Inhibition of the negative effect of high glucose on osteogenic differentiation of bone marrow stromal cells by silicon ions from calcium silicate bioceramics

Osteogenesis of bone marrow mesenchymal stem cell in hyperglycemia

Diabetes mellitus (DM) has been shown to be a clinical risk factor for bone diseases including osteoporosis and fragility. Bone metabolism is a complicated process that requires coordinated differentiation and proliferation of bone marrow mesenchymal stem cells (BMSCs). Owing to the regenerative properties, BMSCs have laid a robust foundation for their clinical application in various diseases. However, mounting evidence indicates that the osteogenic capability of BMSCs is impaired under high glucose conditions, which is responsible for diabetic bone diseases and greatly reduces the therapeutic efficiency of BMSCs. With the rapidly increasing incidence of DM, a better understanding of the impacts of hyperglycemia on BMSCs osteogenesis and the underlying mechanisms is needed. In this review, we aim to summarize the current knowledge of the osteogenesis of BMSCs in hyperglycemia, the underlying mechanisms, and the strategies to rescue the impaired BMSCs osteogenesis.

Mapping Knowledge Landscapes and Emerging Trends of the Links Between Bone Metabolism and Diabetes Mellitus: A Bibliometric Analysis From 2000 to 2021

Background

Diabetes mellitus (DM) have become seriously threatens to human health and life quality worldwide. As a systemic metabolic disease, multiple studies have revealed that DM is related to metabolic bone diseases and always induces higher risk of fracture. In view of this, the links between bone metabolism (BM) and DM (BMDM) have gained much attention and numerous related papers have been published. Nevertheless, no prior studies have yet been performed to analyze the field of BMDM research through bibliometric approach. To fill this knowledge gap, we performed a comprehensive bibliometric analysis of the global scientific publications in this field.

Methods

Articles and reviews regarding BMDM published between 2000 and 2021 were obtained from the Web of Science after manually screening. VOSviewer 1.6.16, CiteSpace V 5.8.R3, Bibliometrix, and two online analysis platforms were used to conduct the bibliometric and visualization analyses.

Results

A total of 2,525 documents including 2,255 articles and 270 reviews were retrieved. Our analysis demonstrated a steady increasing trend in the number of publications over the past 22 years (R2 = 0.989). The United States has occupied the leading position with the largest outputs and highest H-index. University of California San Francisco contributed the most publications, and Schwartz AV was the most influential author. Collaboration among institutions from different countries was relatively few. The journals that published the most BMDM-related papers were Bone and Osteoporosis International. Osteoporosis and related fractures are the main bone metabolic diseases of greatest concern in this field. According to co-cited references result, “high glucose environment,” “glycation end-product” and “sodium-glucose co-transporter” have been recognized as the current research focus in this domain. The keywords co-occurrence analysis indicated that “diabetic osteoporosis,” “osteoarthritis,” “fracture risk,” “meta-analysis,” “osteogenic differentiation,” “bone regeneration,” “osteogenesis,” and “trabecular bone score” might remain the research hotspots and frontiers in the near future.

Conclusion

As a cross-discipline research field, the links between bone metabolism and diabetes mellitus are attracting increased attention. Osteoporosis and related fractures are the main bone metabolic diseases of greatest concern in this field. These insights may be helpful for clinicians to recognize diabetic osteopenia and provide more attention and support to such patients.

Chrysin Attenuates High Glucose-Induced BMSC Dysfunction via the Activation of the PI3K/AKT/Nrf2 Signaling Pathway

Purpose

High glucose environment in diabetes mellitus induces the dysfunction of bone marrow-derived mesenchymal stromal cells (BMSCs) and impairs bone regeneration. Chrysin is a natural polyphenol with outstanding anti-inflammation and anti-oxidation ability. However, whether and how chrysin affects BMSCs in high glucose conditions remain poorly understood. The present study aimed to explore the effects and underlying mechanisms of chrysin on the BMSCs exposed to high glucose environment.

Materials and Methods

Cell viability was detected by cell counting kit 8 assay and 5-ethynyl-2’-deoxyuridine staining, while cell apoptosis was determined through flow cytometry using Annexin V-FITC/PI kit. The oxidative stress in BMSCs was evaluated by detecting the reactive oxygen species production, malondialdehyde content, and superoxide dismutase activity. Alkaline phosphatase staining, Alizarin Red staining, and quantitative real-time PCR were performed to determine the osteogenic differentiation. Western blot was used to examine the expression of the PI3K/ATK/Nrf2 signaling pathway. Furthermore, chrysin was injected into calvarial defects of type 1 diabetic SD rats to assess its in vivo bone formation capability.

Results

Chrysin reduced oxidative stress, increased cell viability, and promoted osteogenic differentiation in BMSCs exposed to high glucose. Blocking PI3K/ATK/Nrf2 signaling pathway weakened the beneficial effects of chrysin, indicating that chrysin at least partly worked through the PI3K/ATK/Nrf2 pathway.

Conclusion

Chrysin can protect BMSCs from high glucose-induced oxidative stress via the activation of the PI3K/AKT/Nrf2 pathway, and promote bone regeneration in type 1 diabetic rats.

Surface engineering of titania nanotubes incorporated with double-layered extracellular vesicles to modulate inflammation and osteogenesis

Titania nanotubes (TNT) generated on titanium implant are emerged as important modification technique to facilitate bone regeneration. Mesenchymal stem cells (MSCs)-derived exosomes are membrane bound extracellular vesicles (EVs), which play an important role in tissue regeneration. The objective of this study was to generate an EVs hybrid TNT aiming at regulating inflammation, MSCs recruitment and osteogenesis. We isolated EVs from MSCs (MSCs EVs) and 3-day osteogenically differentiated MSCs (3d EVs). MSC EVs and 3d EVs exhibited round morphology under TEM, which also showed robust internalization by human bone marrow derived MSCs (hBMSCs). Next, we fabricated 3d EVs/MSC EVs hybrid TNT. When inflammatory macrophages were co-cultured with EVs hybrid TNT, the gene and protein expression of inflammatory cytokine were significantly reduced. Macrophage morphology was also examined by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Further migratory ability study using hBMSCs indicated significant enhancement of MSCs migration in EVs hybrid TNT. In addition, we further demonstrated significant increase of osteogenic differentiation of hBMSCs in EVs hybrid TNT. This study suggests that EVs hybrid TNT may serve as a viable therapeutic approach to enhance osteogenesis and bone regeneration.

Cytocompatibility and bioactive properties of the new dual-curing resin-modified calcium silicate-based material for vital pulp therapy

OBJECTIVE

The aim of the present study was to evaluate the in vitro biocompatibility of Theracal PT, Theracal LC, and MTA Angelus, considered as bioactive materials used for vital pulp treatment, on human dental pulp stem cells (hDPSCs).

MATERIALS AND METHODS

Human dental pulp stem cells (hDPSCs) were isolated from third molars, and material eluates were prepared (undiluted, 1:2, and 1:4 ratios). The hDPSC cytotoxicity, adhesion, morphology, viability, and cell migration were assessed. The mineralization nodule formation was determined by Alizarin red S staining (ARS). The odonto/osteogenic differentiation potential was assessed by osteo/odontogenic marker expression real-time qPCR. The chemical composition and ion release of the vital pulp materials were determined by energy dispersive X-ray (EDX) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Statistical differences were assessed by ANOVA and Tukey's test (p < 0.05).

RESULTS

The three vital pulp materials showed variable levels of calcium, tungsten, silicon, and zirconium release and in their chemical composition. Cytocompatibility assays revealed higher hDPSC viability and migration rates when treated with Theracal PT than with Theracal LC. The lowest cell adhesion and spreading were observed in all Theracal LC-treated groups, whereas the highest were observed when treated with MTA. Theracal PT and MTA promoted the upregulation of DSPP and RUNX2 gene expression (p < 0.05). After 21 days, both MTA Angelus and Theracal PT-treated cells exhibited a significantly higher mineralized nodule formation than the negative control (p < 0.05).

CONCLUSIONS

This study demonstrates the favorable in vitro cytocompatibility and bioactive properties of the recently introduced Theracal PT and the well-established MTA Angelus on hDPSCs, as opposed to Theracal LC. More studies, including in vivo animal testing are suggested before these new formulations might be used in the clinical setting.

CLINICAL RELEVANCE

Theracal PT is a new material that could be clinically suitable for vital pulp therapy. Further studies considering its biocompatibility and bioactivity are necessary.

Semaphorin3B Promotes Proliferation and Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells in a High-Glucose Microenvironment

Bone marrow mesenchymal stem cells (BMSCs) play an essential role in osteogenesis and bone metabolism and have already been recognized as one of the most popular seed cells for bone tissue engineering for bone diseases. However, high-glucose (HG) conditions in type 2 diabetes mellitus (T2DM) exert deleterious effects on BMSC proliferation and osteogenic differentiation. Semaphorin 3B (Sema3B) increases osteoblast differentiation in bone metabolism. Here, we determined the role of Sema3B in the proliferation and osteogenic differentiation of BMSCs in the HG microenvironment. The HG microenvironment decreased Sema3B expression in BMSCs. Moreover, HG inhibited BMSC proliferation. Furthermore, HG inhibited osteogenic differentiation in BMSCs by decreasing the expression of bone formation markers, alkaline phosphatase (ALP) activity, and mineralization. However, the administration of recombinant Sema3B reversed all of these effects. Moreover, our study found that Sema3B could activate the Akt pathway in BMSCs. Sema3B rescues defects in BMSC proliferation and osteogenic differentiation in the HG microenvironment by activating the Akt pathway. These effects were significantly reduced by treatment with an Akt inhibitor. Together, these findings demonstrate that Sema3B promotes the proliferation and osteogenic differentiation of BMSCs via the Akt pathway under HG conditions. Our study provides new insights into the potential ability of Sema3B to ameliorate BMSC proliferation and osteogenic differentiation in an HG microenvironment.